The present invention relates to computer software utility programs, and more specifically to a three-dimensional arrow tool to guide fly through motion inside a digital mockup.
Graphically representing motion inside a three-dimensional digital mockup on a computer display can be difficult due to the number of parameters that must be simultaneously managed. In addition, a camera view of a digital mockup offers few, if any, points of reference to guide motion. Without a point of reference, it is easy for an operator to become disoriented within the scene.
Realistic emulation of motion inside a graphical mockup typically includes emulation of the movements of a camera in the scene. In addition, a velocity indicator and proximity detection can enhance motion emulation. Proximity detection can include a point of impact in relation to the camera located at a point from which the three-dimensional digital mockup is being viewed. This camera can also be inclusive of a virtual structure that is being manipulated to alter the view, for example, piloting an airplane, driving a car, operating a tool or other in screen device.
In particular, it is difficult to effect three-dimensional motion inside a digital mockup using a two dimensional pointing device such as a mouse. Other software tools designed to implement three-dimensional motion using a two dimensional pointing device can be awkward to use and unintuitive. For example, it is known to use a two dimensional compass and gauge in close proximity to a navigation tool. A motion direction is then issued from the mouse location. The two visual devices appear on screen, such as a gauge and a compass, to indicate course and azimuth. The known art, however, makes it difficult on a human operator to evaluate simulated motion in an instinctive manner. The operator is forced to perform a conversion from two dimensional features to a three dimensional trajectory. These previously known methods require a user to follow multiple information feedback at one time. A human operator can find it difficult to simultaneously track the compass and the mouse location.
Other previously known approaches include the use of an alternate pointing device such as a joystick. However, this can require additional hardware equipment than that normally deployed on a computer system. In addition, it requires an operator to relocate their hand from one pointing device to the other each time the user needed to effect a simulated motion.
It would be useful, therefore, to have a three dimensional software tool using a standard pointing device to evaluate direction of motion, speed, proximity of virtual objects and collisions during fly motion inside a three-dimensional digital mockup.
Accordingly, the present invention provides a method and apparatus for guiding flight through a computer digital mockup object scene generated on a display. A three dimensional graphical figure, such as an arrow can be formed on the display to represent a trajectory responsive to positioning of a cursor with an input device. The three dimensional graphical figure can be bent responsive to rotation speed of a viewpoint; and stretched or compressed responsive to viewpoint translation speed.
In one embodiment, the three dimensional graphical figure formed is an arrow with a head part and base part. In one aspect the visual texture of the three dimensional graphical figure can be altered to indicate an imminent collision of the viewpoint with an object in the digital mock up scene. Altering the texture can include changing the color, presenting a pattern or changing the shape. An imminent collision can be determined by computing the viewpoint eye translation along its sight direction and testing the resulting eye position against the depth buffer.
In another aspect, the three dimensional graphical figure can be vibrated back and forth responsive to a collision of the viewpoint with an object in the digital mockup scene. The three dimensional graphical figure can be implemented using multiple slices.